Acute myocardial infarction (AMI) is a leading cause of morbidity and mortality worldwide. In Germany alone the incidence is about 280.000 cases per year. The treatment of a patient who has an AMI comprises the opening of the occluded coronary artery by reperfusion therapy combined with the administration of thrombocyte aggregation inhibitors and coagulation inhibitors to prevent the reclosure of the vessel. Further the pulse and blood pressure can be lowered through administration of beta-blockers and ACE inhibitors. Also common is the use of statins for lowering of the cholesterol level. The medical approach for a direct repair of the heart muscle is currently limited to the experimental use of body's own bone marrow cells. There is a great need for drugs with a similar effect without the use of bone marrow cells.
The tissue necrosis sustained during AMI triggers a wound healing response that leads to a replacement of the necrotic area with granulation tissue and eventually a collagen-rich scar. Monocytes are recruited from the bone marrow into the infarcted myocardium and play important roles during wound healing after AMI. The monocyte response in the myocardium is temporally biphasic. Pro-inflammatory monocytes appear earlier and promote digestion of infarcted tissue and removal of necrotic debris, whereas reparative monocytes dominate later and propagate angiogenesis and repair. Cell surface expression of the chemokine receptor CXCR4 identifies a reparative monocyte subset in mice and humans. Pro-angiogenic and pro-healing effects of CXCR4+ myeloid cells are thought to be mediated via secreted proteins acting in a paracrine manner, but the identity of these Factors was largely unknown. Therefore, the inventors conducted a bioinformatic secretome analysis in human CXCR4+ bone marrow cells to identify novel secreted proteins controlling infarct healing and showing therapeutic potential after AMI.
These studies identified two different polypeptides exhibiting pro-angiogenic and/or cytoprotective effects which were named Factor 1 and Factor 2 proteins by the Inventors.
Both Factors were described in several scientific publications referring to a biological context which does not comprise the pro-angiogenic and/or cytoprotective effects of these Factors in non-transformed cells or non-transformed tissues. None of the studies discloses evidence for or even a hint at a function of these Factors or a significant correlation of one of the Factors with a disease or condition associated exclusively with non-transformed cells or non-transformed tissue.
The amino acid sequence of human Factor 1 is encoded in open reading frame 10 on human chromosome 19 (C19Orf10). The Protein was described in 2007 in a proteom-analysis of the so called fibroblast-like synoviocytes (FLS-cells) as a new secreted Factor in the synovium. A correlation between the secretion of the protein and inflammatory diseases of the joint has been supposed without any experimental or statistical evidence (Weiler et al., Arthritis Research and Therapy 2007, The identification and characterization of a novel protein, c19orf10, in the synovium). A corresponding patent application claims the protein as therapeutic agent for the treatment of joint and for the diagnosis of a tissue undergoing altered growth as well as monitoring changes in a tissue (US 2008/0004232 A1, Characterization of c19orf10, a novel synovial protein). Another scientific publication describes an enhanced expression of the protein in hepatocellar carcinoma cells (Sunagozaka et al., International Journal of Cancer, 2010, Identification of a secretory protein c19orf10 activated in hepatocellular carcinoma). Recombinant produced protein showed a proliferation enhancing effect on cultured hepatocellar carcinoma cells. It is noted that C19Orf10 has also been referred to as IL-25, IL-27 and IL-27W as it was originally considered an interleukin. However, the terms “IL-25” and “IL-27” have been used inconsistently in the art and have been used to designate a variety of different proteins. For example, US 2004/0185049 refers to a protein as IL-27 and discloses its use in modulating the immune response. This protein is structurally distinct from Factor 1 (compare Factor 1 amino acid sequence according to SEQ ID NO: 1 to the amino acid sequence of “IL-27” according to UniProt: Q8NEV9). Similarly, EP 2 130 547 A1 refers to a protein as IL-25 and discloses its use in treating inflammation. This protein has also been referred to in the art as IL-17E and is structurally distinct from Factor 1 (compare the amino acid sequence of Factor 1 according to SEQ ID NO: 1 to the amino acid sequence of “IL-25” according to UniProt: Q9H293).
The amino acid sequence of human Factor 2 is encoded in open reading frame 63 on human chromosome 19 (C19Orf63). The protein was described in 2009 as new secreted Factor INM02 (Wang et al., Journal of Endocrinology 2009, Molecular cloning of a novel secreted peptide, INM02, and regulation of its expression by glucose). The presence of the protein was shown in human serum with polyclonal antibodies. Further, a correlation between the expression of the protein in cultured MIN6 (beta-cells) as well as in isolated pancreatic rat islets and the glucose concentration in the medium was shown. An analysis of the correlation between diabetes and the expression of INM2 provided no significant results. A corresponding patent application claims the production of polyclonal antibodies against the protein and the use for the treatment of diabetes mellitus (CN 200910055490, Novel polyclonal antibody of secretive peptide INM02 and preparation method thereof).
Another scientific publication described the protein as a new secreted Factor hHSS1 (human Hematopoietic Signal peptide-containing Secreted 1) (Junes-Gill et al., J Neurooncol, 2011, hHSS1: a novel secreted factor and suppressor of glioma growth located at chromosome 19q13.33). The published data shows an expression of hHSS1 in stem cells of the hematopoietic system and suggest a function as tumor-suppressor in the genesis of particular brain tumors (gliomas). A corresponding patent application claims the use of hHSS1 in the treatment of brain tumors (WO2011/094446 A1, A method for treating brain cancer using a novel tumor suppressor gene and secreted factor).